Flat panel displays generally use a gate driving circuit or a gate drive on array (GOA) consisting of a plurality of cascaded shift registers. Since characteristics of the GOA, when a shift register fails, a whole row of pixels which are connected with the failed shift register will turn into an abnormal display status, thereby causing a failed display panel. At this time, recovering of the failed shift register on an array substrate is required.
In a conventional GOA, a recovering signal line (Recover) which is connectable with each gate line (Gate) is added, as shown in FIG. 1a and FIG. 2a. When the shift register in a (n+1)th stage fails, recovering of the failed shift register is required. FIG. 1b and FIG. 2b show arrangements of a gate driving circuit after recovering the shift register in the (n+1)th stage respectively, in which “x” indicates for disconnecting, and “●” indicates for connecting. In particular, a recovering method shown in FIG. 1b is to disconnect a signal outputting terminal (Output) of the shift register in the (n+1)th stage from a corresponding gate line (Gate n+1), from a resetting signal terminal (Reset) of the shift register in a previous stage, and from a signal inputting terminal (Input) of the shift register in a next stage, and to connect a recovering signal line (Recover) to the gate line (Gate n+1). The recovering method shown in FIG. 2b is to disconnect the signal outputting terminal (Output) of the shift register in the (n+1)th stage from the Gate n+1, from the resetting signal terminal (Reset) of the shift register in a nth stage, and from the signal inputting terminal (Input) of the shift register in the (n+2)th stage, and to connect the recovering signal line (Recover) to a source of a recovering switch transistor (T n+1).
FIG. 3a shows a timing diagram before the recovering and FIG. 3b shows a timing diagram after the recovering. Since the recovering signal line (Recover) is throughout the whole GOA in the recovering methods discussed above, the recovering signal line (Recover) is connectable with all signal outputting terminals (Output), and thereby a parasitic capacitor may be generated at a connection point. Furthermore, the above recovering methods replace a signal outputted from the failed shift register by using the recovering signal line (Recover), thus a load of the whole row of pixels on the gate line connected with the recovering signal line (Recover) and the load at the connection point between the recovering signal line (Recover) and each signal outputting terminal (Output) will cause a serious attenuation of a signal transmitted on the recovering signal line (Recover), thereby affecting the recovering of the failed shift register.